diff --git a/testbench.ipynb b/testbench.ipynb
index ae6c9f1..f941874 100644
--- a/testbench.ipynb
+++ b/testbench.ipynb
@@ -27,12 +27,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 3,
    "id": "207d2510",
    "metadata": {},
    "outputs": [],
    "source": [
     "import os\n",
+    "import re\n",
     "import shutil\n",
     "import markdown\n",
     "import yaml\n",
@@ -88,11 +89,96 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 14,
+   "id": "9abb76b2",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def find_cyclical_placeholders(s, _parents = None, _leaves = None, **kwargs):\n",
+    "    if _parents is None:\n",
+    "        _parents = tuple()\n",
+    "    if _leaves is None:\n",
+    "        _leaves = {}\n",
+    "    placeholders = extract_placeholders(s)\n",
+    "\n",
+    "    if placeholders is None or len(placeholders) == 0:\n",
+    "        _leaves[_parents] = False\n",
+    "\n",
+    "    for p in placeholders:\n",
+    "        if p in _parents:\n",
+    "            _leaves[_parents + (p,)] = True\n",
+    "        else:\n",
+    "            find_cyclical_placeholders(\n",
+    "                ('{'+p+'}').format(**kwargs),\n",
+    "                _parents = _parents+(p,),\n",
+    "                _leaves = _leaves,\n",
+    "                **kwargs\n",
+    "            )\n",
+    "\n",
+    "    return _leaves\n",
+    "        \n",
+    "        \n",
+    "\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 16,
+   "id": "8699f542",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "{('a',): False, ('b',): False, ('c', 'd'): False, ('c', 'e', 'c'): True}"
+      ]
+     },
+     "execution_count": 16,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "kwargs = {'a': '1', 'b': '2', 'c': '{d}+{e}', 'd': '3', 'e': '{c}'}\n",
+    "s = '{a} + {b} = {c}'\n",
+    "find_cyclical_placeholders(s, **kwargs)\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
    "id": "92310172",
    "metadata": {},
    "outputs": [],
-   "source": []
+   "source": [
+    "def extract_placeholders(s):\n",
+    "    # Regex pattern to match placeholders\n",
+    "    placeholder_pattern = r'\\{(\\w+)\\}'\n",
+    "    \n",
+    "    # Find all matches in the string\n",
+    "    matches = re.findall(placeholder_pattern, s)\n",
+    "    \n",
+    "    return matches\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "e6884a45",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "\n",
+    "FOR FORMAT_HTML_TEMPLATE:\n",
+    "unformatted = ...\n",
+    "formatted = None\n",
+    "filled_placeholders = set()\n",
+    "while unformatted != formatted:\n",
+    "    placeholders = extract_paceholders(unformatted)\n",
+    "    formatted = unformatted.format(...)\n",
+    "    filled_placeholders.add(set(placeholders))"
+   ]
   },
   {
    "cell_type": "code",